Variable camber does stall at a higher AoA than Kruger flaps. In a stall, ailerons are still effective when placing krugers inboard and VC outboard (other factors also contribute to this), so it is not just the 747 which has this setup. For this reason the rudder is not used in a stall the same way on large transport aircraft as it is on a light aircraft. I believe this is a FAR25 requirement.
(This is how it is tought JAR ATPL students anyway)
As mentioned, Kruger flaps are flat:
as
variable camber flaps are ... variable camber:
(for some reason the above picture will not insert. See
http://www.!!!!!!!!!!!!!!/open.file/352855/M)